Memories of my childhood birthdays are always of a packed house full of friends and family, sunshine (I’m a late Spring baby), and my mom’s homemade sheet cake for dessert. This chocolate sheet cake recipe brings me right back in the best way! It’s my favorite one-bowl chocolate cake recipe baked perfectly flat in a 9×13 pan, topped with fudgy chocolate frosting and rainbow sprinkles for celebratory effect. It’s the perfect easy dessert recipe for birthdays or any event where you need to feed a crowd.
One Reader, Regina, says: “This turned out soooo good!! I had a last minute gathering at my home for my friend’s wedding with lots of people and needed a good sheet cake recipe. I whipped this up super fast with ingredients I already had at my home and it’s one of the best cakes I’ve ever made.” ★★★★★
It happens to be my birthday week, and I ended up making this chocolate sheet cake to celebrate! It was a total hit.
Moist & Decadent Chocolate Sheet Cake
This recipe starts with whipping up a batch of my favorite chocolate cake, which is so easy to throw together. It’s a one bowl cake made with simple ingredients you probably already have in your pantry, yet it yields the most moist, decadent chocolate cake ever. The texture is so rich, satisfying, and truly everything you could want in a chocolate cake.
The only change I made to bake this recipe as a sheet cake was to reduce the oven temperature to 325ºF (163ºC). The original recipe has you set the oven to 350ºF (177ºC), but when I baked the sheet cake at this temperature, the center rose and domed to the point where I had to invert the sheet cake on a cooling rack to flatten it out. Not the worst thing in the world, but I wanted it to bake as flat as possible. Reducing the oven temperature did the trick and I’m so happy with the results!
Chocolate Sheet Cake Ingredients & Substitutions
This chocolate sheet cake uses simple ingredients you probably already have on-hand. I’ve provided some ingredient substitutions below as well, just in case.
- All Purpose Flour. Otherwise known as plain flour, this creates gluten and helps build structure for the cake. I know that most of my other cake recipes call for cake flour, but I like to use all-purpose flour for my chocolate based cakes. It yields the best texture.
- Cocoa Powder. Adds rich chocolate flavor to this cake. You can use either natural unsweetened cocoa powder OR Dutch-processed cocoa powder interchangeably in this recipe.
- Granulated Sugar. Not only sweetens the cake but helps soften the overall cake texture.
- Baking Soda + Baking Powder. The leavening agents that help this cake rise.
- Vegetable Oil. Provides a good amount of moisture for this cake. I like to use plain vegetable oil, but you can use any clear cooking oil that you prefer. Just keep in mind that whatever you use might flavor the cake, so choose something you love and are used to baking with.
- Large Eggs. To bind the ingredients together. If you need an eggless chocolate sheet cake, you can bake this recipe in a 9×13 pan.
- Pure Vanilla Extract. Adds dimension to the chocolate flavor of this cake.
- Full-Fat Buttermilk. Provides tons of moisture while binding the ingredients together. If you don’t have buttermilk on-hand, you can easily make your own by adding 1 Tablespoon of white vinegar or lemon juice into a liquid measuring cup, then topping it with whole milk until you measure out 1 Cup. Stir it together and let it come to room temperature. Keep in mind that it will end up looking curdled, but that’s what we want!
- Hot Coffee. This helps bring all of the ingredients together into a cohesive batter at the end of the recipe, and the heat of the coffee blooms the cocoa powder to bring out the beautiful chocolate notes. Coffee also amplifies the chocolate flavor with its natural flavor, but you don’t end up tasting coffee in the final baked cake. If you’d rather not use coffee, you can use an equal amount of hot water instead. And if you’re using instant coffee or espresso powder, just follow the instructions on the container to make 1 Cup (8oz) of coffee. It’s usually one heaping teaspoon per 8 oz of water.
Fudgy Chocolate Frosting
This chocolate cake is made even more decadent with a generous helping of fudgy chocolate frosting. Every bite melts in your mouth.
This chocolate buttercream frosting is a super simple recipe that uses a handful of ingredients and comes together in just 10 minutes. Although it is an American buttercream recipe, I reduced the powdered sugar amount a ton so that the frosting isn’t too sweet, but still the perfect consistency for decorating the cake.
How to Decorate a Chocolate Sheet Cake
I kept things simple with this chocolate sheet cake and it turned out so celebratory! I frosted it with the fudgy chocolate buttercream and used an angled spatula to add some rustic swirls and texture. Then, I added the remaining chocolate buttercream into a piping bag fitted with Wilton Tip 4B and piped a shell border around the entire edge of the cake.
Finally, I added rainbow sprinkles to the shell border to add some fun color.
This design is perfect for adding a birthday message in the middle, topping with candles, or keeping as-is! No matter how you decorate, this chocolate sheet cake is bound to be a hit with any chocolate lover.
Chocolate Sheet Cake
Equipment
Ingredients
Chocolate Sheet Cake
- 2 Cups (265g) all purpose flour
- 1 2/3 Cups (340g) granulated sugar
- 2/3 Cup (60g) unsweetened natural cocoa powder Dutch-processed cocoa powder works too!
- 2 tsp baking soda
- 1 tsp baking powder
- 1/2 tsp kosher salt
- 1/2 Cup (120ml) vegetable oil
- 2 large eggs, room temperature
- 1 1/2 tsp pure vanilla extract
- 1 Cup (240ml) full-fat buttermilk*, room temperature DIY recipe in the notes
- 1 Cup (240ml) hot coffee or hot water
Chocolate Buttercream
- 1 1/2 Cups (339g) unsalted butter, room temperature
- 4 Cups (480g) powdered sugar
- 3/4 Cup (68g) natural unsweetened cocoa powder
- 4 Tbsp whole milk, room temperature
- 1 Tbsp pure vanilla extract
- pinch of salt, or to taste
Garnish (Optional)
- 3 Tbsp rainbow sprinkles
Instructions
Make the Chocolate Sheet Cake
- Preheat the oven to 325ºF and prepare a 9×13 metal pan or baking dish* by spraying the sides with baking spray and lining the bottom with parchment paper
- Place all of the dry ingredients into the bowl of a stand mixer and stir on low for 30 seconds to fully combine them. Add the vegetable oil, eggs, vanilla, and buttermilk and mix on low until just combined. With the mixer still on low, add the hot coffee (or hot water) in a slow stream, then turn the mixer to medium and beat until smooth, about 2 minutes. The batter will be very thin.
- Pour into the prepared pan and bake for 35-40 minutes, until a toothpick inserted comes out clean. Cool completely before frosting. You can either let it cool in the pan before decorating or remove it from the pan to decorate if you wish.
Make the Chocolate Buttercream
- In a stand mixer fitted with a paddle attachment, whip the butter on medium-high speed until creamy and light in color, 4-5 minutes.
- Scrape down the bowl and paddle, then add half of the powdered sugar and half of the cocoa powder. Cover the mixer with a clean kitchen towel (to prevent ingredients flying out of the bowl), then turn the mixer to low speed and mix until the ingredients start to come together.
- Scrape down the bowl and paddle and add the rest of the powdered sugar and cocoa powder, and also the milk, salt, and vanilla extract. Cover the mixer with the kitchen towel once more and turn the mixer to low speed. Mix until the ingredients are combined.
- Remove the kitchen towel, scrape down the bowl and paddle, then continue mixing on low speed until uniform and smooth, 2-3 minutes.
Assembly
- Once the chocolate sheet cake is cooled completely, frost with the chocolate buttercream. To create the look pictured, use half of the chocolate buttercream to frost the cake surface with rustic texture. Add the remaining chocolate buttercream into a piping bag fitted with Wilton Tip 4B and pipe a shell border around the edges of the cake. Garnish with rainbow sprinkles.
Notes
- The chocolate sheet cake can be made ahead and stored at room temperature, covered tightly in plastic wrap, for up to two days. Alternatively, you can cover with plastic wrap and store in the freezer for up to two months before thawing to room temperature.
- The chocolate buttercream can be made ahead and stored in an airtight container at room temperature for up to 1 day. Alternatively, you can store it in an airtight container in the refrigerator for up to two weeks. When you’re ready to use it, bring it back to room temperature and rewhip with your stand mixer to bring back to frosting consistency.
- The frosted sheet cake can be stored at room temperature, covered with plastic wrap or aluminum foil, for up to five days.
Great recipe. I made this for my daughter’s first birthday party and received so many compliments. What keeps the cake so moist?
Yay, Olivia! I believe it’s the vegetable oil and buttermilk that keeps this cake deeply moist for days. I’m so glad it was a hit!
This cake was delicious! It was easy, a little messy, but overall good. The only thing is if you want to do the piping on the sides of the cake the frosting isn’t enough. Or at least it wasn’t for me. I had to make two cakes and the only reason I had enough frosting for the sides was because I had to make a double batch.
So happy you loved this recipe, Laura! Did you remove the cake from the pan and frost the sides? The amount of buttercream in the recipe is just enough for the top of the cake and the piping around the edges (I kept it in the pan).
looks great! question, however; how would i divide the ingredients if i have a 8x8in baking pan instead of a 9×13 pan?
Hi Cody! You can half the ingredients for an 8×8 inch pan. I would start checking for doneness around the 25 minute mark since the pan size will be smaller. Hope that helps!
I love your cake recipes, I’ve made a few now and they are always a hit! I’m curious, can this cake be removed from the pan and used to cut into a shape/mini cakes or is it too delicate?
Hi Lisa! Thanks for the kind words about my recipes! This cake can definitely be cut into a shape or mini cakes, it’s not too delicate. Enjoy!
Hi. Do you have a version of this cake without chocolate, that bakes to the same height? I want to use the side by side to make one cake with two different flavours.
Hi Jan! I have a vanilla sheet cake recipe here: https://sugarandsparrow.com/vanilla-sheet-cake-recipe/
Lovely cake. I made it for my brother’s birthday today and everybody loved it!!! 10/10 would bake again.
Yay, Caroline! So happy it was a hit!
This turned out soooo good!! I had a last minute gathering at my home for my friend’s wedding with lots of people and needed a good sheet cake recipe. I whipped this up super fast with ingredients I already had at my home and it’s one of the best cakes I’ve ever made.
Yay, Regina!! I’m so happy it was such a hit and you were able to pull off a last minute gathering with ease 🙂 thanks for letting me know!
Easy recipe but results are sure to impress. Cake and icing were both decadent with the use of simple pantry ingredients.
Yay, Min! So happy you loved this recipe!
Super excited to try this for my daughter’s birthday this weekend – could we use cocao powder instead of cocoa?
Hi Kyleigh! I haven’t tried that myself but I read that you can substitute cacao powder for cocoa powder in baking recipes. It might have more of an intense flavor, but if cacao powder is what you normally use for baking recipes I’d say go for it!
I love the look of this cake! I have a half sheet cake pan with lid that I would like to use to feed everyone at work. How would you adjust your recipe for 13×18? I dont plan to remove it from the pan, should I skip baking nails and bake low and slow?
Hi Kelly! I’m excited for you to try this recipe! I’ve never baked it in a larger pan than 9×13, but if your half sheet pan has taller sides (2″ sides) I would double the recipe and use flower nails to keep the baking even. Bake at 325F and start checking for doneness at the 40 minute mark. If your pan has shorter sides you might be able to keep the recipe measurements as-is, skip the flower nails, and check for doneness around the 20 minute mark (you wouldn’t need as much baking time with a shorter layer). Hope that helps!
Hello Whitney,
I just try baking it in 40x30x5cm for about 35-40 minutes, mine was baked at 38 minutes. it works perfectly and the height is 3.5 cm.
Thanks so much for reporting back, May! I’m so happy this recipe worked in that pan size.
Hi, this looks delicious! Could I use melted butter instead of oil? Thanks.
Hi Nat! I haven’t tried that myself but it should work! Let me know if you try it 🙂
I use butter in all my baked goods instead of oil..works perfectly.
Thanks so much for the info, Linda! Now I want to try it!